Switchboard construction having adjustable grommet wire holders



Sept. 23, 1947. A. J. A. PETERSON ETAL. 2,427,742

SWITCHBOARD CONSTRUCTION HAVING ADJUSTABLE GROMM ET WIRE HOLDERS Filed March 12, 1943 2 Sheets-Shet 1 L i H WITNESSES: [NVENTORS g4 I fl f edf 1 Pele/Jon %2%$W ATTOR EY P A. J. A. PETERSON arm. 2,427,742

SWITCHBOARD CONSTRUCTION HAVING ADJUSTABLE GROMMET WIRE HOLDERS Filed March 12, 1945 A 2 Sheets-Sheet 2' I 37' an .497 37 3e WITNESSES: gvswons C ,7/ red eferjafl a rgdjohnl? 60rd W ATTO K ZEY Patented Sept. 23, 1947 SWITCHBOARD CONSTRUCTION HAVING ADJUSTABLE GROMlViET WIRE HOLDERS Alfred J. A. Peterson, Wilkinsburg, and John D. Gard, Irwin, Pa., assignors to Westinghouse Electric Corporation, East Pittsburgh, Pa., a corporation of Pennsylvania Application March 12, 1943, Serial No. 478,896

13 Claims. 1

Our invention relates, generally, to switchboard construction and, more particularly, to the wiring of switchboard panels upon which are mounted instruments, relays and other switchboard devices.

In accordance with one method of switchboard construction which has been used heretofore, each panel comprises a unitary metallic member having one or more of its edges terminating in channel form which serves the dual purpose of making the panel self-supporting and providing a compartment, in the form of a channel well, for containing the conductors which are connected to the apparatus mounted upon the panel. In another method of construction, perforated wiring strips are secured on the rear face of the panel to form with the panel flanges troughs for the vertical runs of wires. The circuit wires enter and leave the trough by way of the perforations in the strip.

Neither of the foregoing methods has proven entirely satisfactory in all cases. Thus, when the former method is utilized, difiiculty is sometimes experienced in locating the proper wires, which are concealed in the wiring channel, when making connections to the terminals of the switchboard apparatus. When the Wires passv through perforations in the wiring strips they might not always be in the best possible position with relation to the terminal studs on the panels to which the wires are to be connected, thereby resulting in a poor appearance and higher cost. Furthermore, projection-mounted instruments and relays of different types may have studs of varyin length, and flush-mounted apparatus may have varying case depths and stud lengths,

thereby making it difiicult to wire a switchboard panel by either of the foregoing methods.

An object of our invention is to provide a method of switchboard construction and wiring which will overcome the foregoing disadvantages of prior methods of construction.

A more specific object of our invention is to provide for so locating the panel wires in an enclosed raceway that they can be drawn from the enclosing raceway at a position directly opposite the terminal studs to which they are to be connected, or in the most preferred position for subsequent wiring on the panel.

Another object of our invention is to provide a Wiring gutter or raceway which is suitable for use on switchboard panels having either flush or projection-mounted apparatus thereon.

A further object of our invention is to provide an enclosure for terminal blocks at the rear of a 2 able position in relation to the cables which connect the circuits to external points.

Other objects of our invention will be explained fully hereinafter or will be apparent to those skilled in the art.

According to one embodiment of our invention, wire gutters are attached to the panel rear flanges. Each gutter is provided with one or more slots extending the length of the gutter. The Wires are retained in the slots in any desired position by grommets, preferably composed of a resilient material and so constructed that they may be shifted along the slots by compressing the grommets with the fingers or a suitable tool. When the pressure is released the grommet returns to its normal shape and is retained in the proper position for the wire by the friction between the grommet and the sides of the slot.

For a fuller understanding of the nature and objects of our invention, reference may be had to the following detailed description, taken in conjunction with the accompanying drawings, in which:

Figure 1 is a View, in rear elevation, of a portion of a switchboard structure embodying our invention;

Fig. 2 is a View, in section, taken along the line 11-11 of Fig. 1;

Fig. 3 is an enlarged view, in elevation, taken along the line III-III of Fig. 2;

Fig. 4 is an enlarged view, in elevation, of one form of the grommets utilized for protecting the wires and retaining them in the proper position in the slots;

Fig. 5 is a view, in section, taken along the line V-V of Fig. 4;

Fig. 6 is an enlarged View of a modified form of grommet;

Fig. '7 is a View, in section, taken along the line VII-VII of Fig. 6;

Fig. 8 is an enlarged View of another modification of the grommet;

Fig. 9 is a view, in section, taken along the line IX-IX of Fig. 8;

Fig. 10 is a View, in section, of a modification of the switchboard structure;

Fig. 11 is an enlarged view, in elevation, of a portion of a wiring gutter having slots of a modifled form therein;

Fig. 12 is an enlarged view of a grommet suitable for use in the slot illustrated in Fig. 11; and

Fig. 13 is aview, in section, taken along the line XIII-XIII of Fig. 12.

Referring to the drawings, and particularly to panel and to locate the terminal blocks in a suit- Fig. 2, the switchboard panel shown comprises a unitary metallic member l having its edges bent at substantially a right angle to the face of the panel and terminating in inwardly bent portions II at the rear of the panel. In this manner the panel is strengthened and made self supporting.v A wiring gutter l2 and a combined terminal and wiring housing l3 are provided at each side of the panel for concealing and supporting the switchboard wires. The wiring gutters and housings may be composed of steel or other suitable material which is pressed into the desired shapes.

As shown, the gutter l2 is L-shaped in section with inbending flanges on. both legs of the L.. The housing I3 is channel-shaped insectionwith.

inbending flanges on both sides of the channel. The gutters and housings may be bolted or welded to the flanges II of the panel H). A removable cover plate I l, which is L-shaped in section, is provided for the gutter l2 and a removable flat cover plate l5 is provided for the housing I3. The cover plates may be secured in position by spring c1ips,. as shown, or. they may be fastened on with screwsor bolts if desired;

As shown in Figs. 1, 2 and 3 the housings l3 are of a greater width than the gutters ii, thereby providing sufiicient space to enclose. terminal. blocks 16 at which wires I! extending from.

cables i 8 terminate. In accordance with. usual practice, switchboard wires I 9 are provided for completing the connections from the. terminal blocks IE to the apparatus mounted on the switchboard panel.

In order to facilitate the Wiring of the switchboard panel as Well asto protect the wires, they. are enclosed in the wiring gutters I2 which con-- tinue from the top-of. thehousings l-3-to the top of the panel. Thus, the wide housings l3 may be extended only as far as is necessary to enclose the required number of termina1 blocks for each panel.

In order that the switchboard wires may be drawn from the wiring gutters and housings at a position directly opposite the terminal studs to which they are connected or in the most preallel to the face of the panel ID or perpendicular.

to the'panel face. Thisarrangement facilitates the making of connections to terminals-which are disposed at a considerable distance'behind the rear face of the panel andalso to terminals which are relatively close to the rear face of the panel. In this manner the wiring connectionsmay be readily made to apparatus of the flush-mounted type as well as of the projectionmountedtype.

In order to protect the wires against abrasion and also to retain the wiresin the desired position in a slot 2|, elongated grommets 23 are provided. The grommets 23 are preferably composed of a resilient material such as rubber or of a suitable plastic, composition, wood, or they mayeven be made from metal. As shown in Figs. 6 and '7, each grommet is elongated in shape and is pro vided with a pair of flanges 24 and ZS-for retaining the grommet in the slot 21- andfor. frictionally engaging the sides of the slot to retain it in an selected position in the slot. The inner flange 24 is considerably narrower than the outer flange 25, thereby permitting the grommet to be inserted in the slot by merely compressing it with thefingers or a suitable tool.

Also, after the grommet is inserted into the slot it may be slid up and down in the slot to the desired position by compressing the sides of the grommet. When the pressure is released the grommet returns to its normal shape and is retained inposition by the friction between the grommet and the sides of the slot.

As shown in Figs. 6 and 7 a groove 26 is provided at each.- end of the grommet, thereby facilitating the compressing of the grommet to enable it to be inserted into the slot. If the grommet'is composed of rubber the grooves 25 are not necessary. However, they are desirable in case the grommet is composed Of plastic or metal.

After the grommet is placed in the desired position substantially opposite the terminals to which the connections are to be made, the wires for making these connections may be drawn through the grommet and the connections completed. As illustrated, the grommets ma be made in several different sizes to accommodate a. different number of wires. It is believed that grommets. holding either two or four wires will be the most practical for switchboard panel wiring. Thus, if only two wires are to be brought out. at acertain position a two wire grommet may beinserted in that position. If four wires are to be. brought out in a. group, a four wire grommet. may be utilized. In case. more than four wires are requiredtwo grommets may be placed end-to-end in a slot. as shown in Fig. 3, thereby permitting all of the wires to be brought out of the gutter relatively close together.

As. shown in. Fig. 2, in the event that it. is desired to make connections between adjacent panels, grommets 21, which have sufficient depth to permit them. to. be inserted in aligned slots in. adjacent wiring gutters, may be utilized. In this manner the wires may be run from a gutter on one panel. to a gutter on an adjacent panel, thereby making the desired cross or. inter-panel connections.

The grommet 3i, shownin Figs. 4 and 5, is of a slightly different construction from the one illustrated in Figs. 6 and 7. It is provided with a slot 32 at one end and an inner flange 33 which is narrower at the end of the grommet opposite the slot 32 than it is at the end containing the slot 32. The flange 33 is narrower at all points than is the outer'flange 34. The slot 32 will permit the grommet to be compressed sufficiently for the wideportionof the inner flange 33 to beinserted'intoa slot in the wiring gutter. When the pressure is released the grommet returns to its normal shape and: the flange 33 retains it in the slot. The structure shown in Figs. 4 and 5 is probably the most suitable in case the grommets are composed of plastic or metal.

In the modification shown in Figs. 8 and 9 the grommet 35' is divided into two sections which are symmetrical in shape; The two halves are normally forced. outwardly against the sides of the slot by. springs 36, one of which is. provided at each end of the grommet. The grommet may be inserted in the slot by compressing the two halves together against the force: of the springs 36. The structure shown in Figs. 8 and-9 is also suitable in casev the grommets are composed of plastic or metal, but is not required in the event that rubber grommets are utilized.

In the modification shown in Fig. the switchboard panel I0 is similar to that shown in Figs. 1 and 2 with the exception that the rearwardly extending flanges are of less depth than in the previously described panel. A panel or the type shown in Fig. 10 is preferably utilized when all or a major portion of the apparatus on the panel is of the projection-mounted type in which the terminals are relatively close to the rear face of the panel. Thus, the wiring gutters H are in a more advantageous position for connecting the panel wires to such terminals. As shown, the wiring slots 21 may be provided in adjacent sides of the gutters to permit the wires to extend either parallel to the rear face of the panel or perpendicular to the rear of the panel in the manner hereinbefore described. In this manner the wires may be brought out of the wiring gutters in the direction which is most suitable for connecting to the proper terminals of the apparatus.

As illustrated in Fig. 11, the sides of the slots 2| may be serrated to assist in holding the grommets 31 in the desired position in the slot. Likewise, the edges of the grommets 31 may be similarly serrated, as shown in Figs. 12 and 13. In this manner, a grommet is prevented from moving vertically in a slot by a wedge action unless the grommet is compressed.

From the foregoing description it is apparent that we have provided an improved method of constructing and wiring switchboard panels which will not only simplify the wiring operation but also materially improve the appearance of the completed panel as compared with previously known methods of panel wiring. Furthermore, the wires are completely protected against abrasion of the insulating covering and the cable terminals as well as the wiring terminal blocks are also fully protected by the enclosed wiring gutters.

Since numerous changes may be made in the above described construction and different embodiments of the invention may be made without departing from the spirit and scope thereof, it

is intended that all matter contained in the foregoing description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

We claim as our invention:

1. A switchboard comprising a panel member, terminals at the rear thereof for electrical apparatus mounted on the panel, a, wiring gutter disposed at the rear of the panel and having a longitudinally extending slot therein, and plurality of elongated grommets slidably disposed in said slot for receiving circuit wires for connection to said terminals, the length of said slot being greater than the total length of the grommets disposed therein, said grommets being expansible to engage the sides of said slot to retain the grommets at any desired position along said slot.

2. A switchboard comprising a panel member, terminals at the rear thereof for electrical apparatus mounted on the panel, a wiring gutter disposed at the rear of the panel and having longitudinally extending slot therein, and a plurality of elongated grommets slidably disposed in said slot for receiving circuit wires for connection to said terminals, the length of said slot being greater than the total length of the grommets disposed therein, said grommets being composed of resilient material and expansible to engage the sides of said slot to retain the grommets at any desired position along said slot.

3. A switchboard comprising a panel member, terminals at the rear thereoi for electrical apparatus mounted on the panel, a wiring gutter disposed at the rear of the panel and having a longitudinally extending slot therein, and a plurality of elongated grommets slidably disposed in said slot for receiving circuit wires for connection to said terminals, the length of said slot being greater than the total length of the grommets disposed therein, said grommets having flanges thereon for retaining them in the slot and being expansible to engage the sides of said slot to retain the grommets at any desired position along said slot.

4. A switchboard comprising a panel member, terminals at the rear thereof for electrical apparatus mounted on the panel, a wiring gutter disposed at the rear of the panel and having a longitudinally extending slot therein, and a plurality of elongated grommets slidably disposed in said slot for receiving circuit wires for connection to said terminals, the length of said slot being greater than the total length of the grommets disposed therein, said grommets being expansible to engage the sides of said slot to retain the grommets at any desired position along said slot and being releasable from said sides for movement in said slot.

5. A switchboard comprising a panel member, terminals at the rear thereof for electrical apparatus mounted on the panel, a wiring gutter disposed at the rear of the panel and having a longitudinally extending slot therein, and a plurality of elongated grommets slidably disposed in said slot for receiving circuit wires for connection to said terminals, the length of said slot being greater than the total length of the grommets disposed therein, said grommets being composed of resilient material expansible for frictionally engaging the sides of said slot to retain the grommets at any desired position along said slot and being'releasable from said sides by pressure for movement in said slot.

6. A switchboard comprising a panel member, terminals at the rear thereof for electrical apparatus mounted on the panel, a wiring gutter disposed at the rear of the panel and having a slot therein, an elongated grommet disposed in said slot for receiving circuit wires for connection to said terminals, said grommet frictionally engaging the sides of said slot to retain the wires in position in said slot and being cut at one end thereof to permit the insertion of the grommet into said slot.

7. A switchboard comprising a panel member, terminals at the rear thereof for electrical apparatus mounted on the panel, a wiring gutter disposed at the rear of the panel and having a slot therein, an elongated grommet disposed in said slot for receiving circuit wires for connection to said terminals, said grommet frictionally engaging the sides of said slot to retain the wires in position in said slot, said grommet being divided into two sections to permit the insertion of the grommet into the slot.

8. A switchboard comprising a panel member, terminals at the rear thereof for electrical apparatus mounted on the panel, a wiring gutter disposed at the rear of the panel and having a slot therein, an elongated grommet disposed in said slot for receiving circuit wires for connection to said terminals, said grommet frictionally engaging the sides of said slot to retain the wires in position in said slot, said grommet being divided into two sections, and resilient means disposed between said sections to permit the insertion of the grommet into the slot.

9. A switchboard comprising a panel member, terminals at the rear thereof for electrical apparatus mounted on the panel, a wiring gutter disposed at the rear of the panel and having a slot therein, an elongated grommet disposed in said slot for receiving circuit wires for connection to said terminals, said grommet being composed of resilient material for frictionally engaging the sides of said slot to retain the wires in position in said slot, said grommet being cut at one end thereof, thereby permitting it to be compressed for insertion into the slot.

10. A switchboard comprising a panel membe having a rearwardly extending flange, terminals at the rear of the panel for electrical apparatus mounted on the panel, a channel-shaped wiring gutter secured to said flange and spaced from the rear of the panel and having a longitudinally extending slot therein, and a plurality of elongated grommets slidably disposed in said slot for receiving circuit wires for connection to said terminals, the length of said slot being greater than the total length of the grommets disposed therein, said grommets being expansible to engage the sides of said slot to retain the grommets at any desired position along said slot.

11. A switchboard comprising a panel member having a rearwardly extending flange, terminals at the rear of the panel for electrical apparatus mounted on the panel, a channel-shaped wiring gutter secured to said flange and spaced from the rear of the panel and having a plurality of longitudinally extending parallel slots in adjacent sides a of the gutter, a part of said slots being in the side of the gutter nearest the rear face of the panel, and a plurality of elongated grommets slidably disposed in each of said slots for receiving circuit wires for connection to said terminals, the length of each slot being greater than the total length of the grommets disposed therein, said grommets being expansible to engage the sides of said slots to retain the grommets at any desired position along said slots.

12. A switchboard comprising a panel member,

terminals at the rear thereof for electrical apparatus mounted onthe panel, a-wiring gutter disposed at the rear ofthe panel and having a slot therein, said slot having serrated sides, and an elongated grommet disposed in said slot for receiving circuit wires for connection to said terminals, said'grommet engaging the sides of said slot to retain the wires in position in said slot.

13. A switchboard comprising a panel member, terminals at the rear thereof for electrical apparatus mounted on the panel, a wiring gutter disposedat the rear of the panel and having a slot therein, said slot having serrated sides, and an elongated grommet disposed in said slot for re ceiving circuit wires for connection to said terminals, said grommet engaging the sides of said slot to retain the wires in position in said slot, the edges of said grommet having serrations therein similar to the serrations in the sides of said slot.

ALFRED J. A. PETERSON. JOHN D. GARD.

REFERENCES CITED The following references are of recordin the file of this patent:

UNITED STATES PATENTS Number Name Date 2,140,376 Anderson Dec. 13, 1938 2,219,887 Bowly et a1 Oct. 29, 1940 2,277,637 Eby Mar. 24, 1942 1,302,137 Cook Apr. 29, 1919 367,730 Seely Aug. 2, 1887 1,697,814 Forbes Jan. 1-, 1929 1,983,368 Hathorn Dec, 4, 1934 1,817,034 Hotchkin Aug. 4, 1931 942,002 Manquais Nov; 30, 1909 2,311,427 Winkelmeyer Feb. 16, 1943 2,104,217 Barnes Jan. 4, 1938 1,882,021 Sauer Oct. 11, 1932 2,186,601 Borkenstein Jan; 9, 1940 1,810,958 Pullman June 23, 1931 2,104,217 Barnes Jan. 4, 1938 2,253,700 Graham Aug. 26, 1941 

